Answer:
5.625 km
Step-by-step explanation:
We can represent the word problem as a pair of equations (system of equations):
5w + 25d = 40
w + d = 2.5
Where w = hours walked, d = hours driven
We can solve it by first isolating the walk variable.
w = 2.5 - d
Substitute it back in for w.
5(2.5 - d) + 25d = 40
12.5 - 5d + 25d = 40
12.5 + 20d = 40
20d = 27.5
d = 1.375
Now we have our hours driven, plug it in for d and solve for w.
w = 2.5 - 1.375
w = 1.125
Hours walked = 1.125 hours
Multiply it by 5 to obtain the distance that the backpacker had walked prior to getting a ride with a motorist.
1.125 × 5 = 5.625
Thus, the backpacker had walked a distance of 5.625 km before getting a ride.